Mineral material such as rock is gained from the earth for processing by exploding or excavating. Rock can also be natural and gravel or construction waste. The processing is typically crushing and/or screening of material. Mobile processing plants and stationary applications are used in the processing. An excavator or wheeled loader loads the material to be processed into a feed hopper of the processing plant from where a feeder feeds the material to be processed in a jaw of a crusher or a screen deck. The material to be processed can also be recyclable material such as concrete, plastic, wood, metal, bricks or asphalt.
Movable material processing plants are track or wheel based and may comprise means for material feeding such as a feed hopper, a feeder, a crusher, a screen and one or more conveyors for conveying processed material for storing or further processing.
A movable processing plant is transported to a working area generally by road on a truck carriage (a track based plant) or truck driven (a wheel based plant). Maximum transport dimensions (length, width, height) are defined in many countries and the transport is requiring special arrangements or is otherwise getting remarkable more difficult when these dimensions are exceeded.
In order to transport the mobile processing plant on road the length, width and height of it are to be put inside prescribed maximum dimensions. Side conveyors beside the processing plant are typically folded along the direction of the body of the processing plant and a joint may be arranged in an output conveyor in the end of the processing plant that the conveyor can be folded in a transport state.
Generally the feeder of the processing plant in its working position is forming the highest point of the processing plant which is why the feeder has to be lowered downwards particularly with movable screening plants in order to get a satisfactory transport height. Folding of wings of the feed hopper inside or outside the feed hopper has been a utilized solution. Putting the side wings in working and transport conditions can often be laborious and time consuming because in some cases they have to be locked in place entirely or partly man powered.
Because at least part of the feeder in the working position is locating above the processing plant the feeder has also to be moved horizontally in relation to the processing plant.
The publication EP1745860 shows a prior art mineral material processing plant comprising a body 112, a track base 121, a processing apparatus 123, a body 120 of the processing apparatus and a feeder 113 having wings which are foldable between transport and working positions.
In the known solution a lower end of the feeder 113 is moving via rails 127 and a sliding surface 110 which is fixed in the body 112. An upper end of the feeder is connected to the body 120 of the processing apparatus 123 via a rail 117 and a joining point 119. The feeder 113 is moving on the rails 117 and 127 which are gently inclined in relation to the horizontal plane so that when lowering the feeder to a transport position the total height is decreasing but due to the gentle angle the total length of the plant is increasing vis-a-vis more. As a result a folding mechanism may be required to be arranged in connection with an output conveyor in the opposite end of the processing plant in order to reach a sufficient short transport length.
An object of the invention is to provide a mineral material processing plant and a fixing structure of the feeder by which problems associated with the prior art may be avoided or at least minimized.